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101.
G. Wang J. Ji Y-B. Wang H. Hu I. P. King J. W. Snape 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,87(5):531-536
Two novel 46-chromosome doubled haploid lines, W66 and M17, derived from separate hexaploid triticale x bread wheat crosses, were characterised using cytological and biochemical markers. Both lines were shown to be relatively stable cytologically, over 11 and 8 generations of selfing, respectively. By examining mitotic and meiotic chromosomes, the stabilities of the two lines were shown to be similar with frequencies of 2n=46 in 74.2–85.5% of cells. However, over selfed generations, the rye chromosomes were shown to have lost some of their heterochromatin, which made it difficult to establish their continued presence using cytological techniques, such as C-banding alone. Cytological evidence from pairing studies, C-banding, and fluorescence in-situ hybridization, showed that both M17 and W66 are wheat/rye multi-addition lines with rye chromosome constitutions of 1R+6R, and 1R+4R, respectively. These conclusions were confirmed by isozyme and storage-protein analysis. 相似文献
102.
正常菌群对常见致病菌拮抗作用的研究 总被引:4,自引:0,他引:4
生物拮抗作用是微生物种群关系研究的一个侧面,实验中我们使用从皮肤上分离的常住菌——痤疮丙酸杆菌(A14-1)和表皮葡萄球菌(F65)对常见致病菌如金黄色葡萄球菌(C189)、绿脓杆菌(C8514)和埃希氏大肠杆菌(C1356)的体外拮抗试验表明,它们具有明显的拮抗作用,拮抗作用一般从48小时开始,72小时明显。而皮肤常住菌间无拮抗作用,相反它们还有协同作用,这对于皮肤的自净以及维持皮肤的微生态平衡具有重要的作用。此外,实验中还进行了乳杆菌和双歧杆菌等正常菌群分离株与上述常见致病菌的体外拮抗试验,结果表明也 相似文献
103.
人抑胃肽的研究:合成和性质 总被引:1,自引:0,他引:1
人抑胃肽的研究:合成和性质崔大敷,崔恒苒,徐明华,曹蕙婷,朱尚权(中国科学院上海生物化学研究所,200031)陈可靖,邓华云(上海医科大学附属中山医院,200032)关键词人抑胃肽,合成,生物活性抑胃肽(简称GIP)最早由Brown等’”从猪小肠分离... 相似文献
104.
酶化学法制备AraA 总被引:3,自引:0,他引:3
AraA中文名称为9-β-D-阿拉伯呋喃糖基腺嘌呤,通常简称为阿糖腺苷,是一种广谱嘌呤核苷类抗病毒药,具有抑制病毒和肿瘤细胞生长的能力。目前,我国主要采用化学全盛法生产AraA。然而用化学合成法生产AraA反就步骤多,使用的试剂对人体危 相似文献
105.
侵染新疆甜菜的两种病毒分离物的研究 总被引:2,自引:0,他引:2
在新疆甜菜的根部和叶片分离到两个球状病毒分离物。从病毒形态、生物学及物化性质等研究结果证明这两个分离物实是一种病毒。病毒粒体力20面体,直径约28nm,回接到甜菜上产生环斑和沿脉线纹最后形成坏死斑。此外还侵染苋色藜,昆诺阿黎,番杏,菠菜等,引起局部坏死斑。在普通烟,心叶烟,菜豆,黄瓜,蕃茄上无症状侵染,病毒致死温度为70℃,10分钟。体外存括期13天以上,冻干病叶7年后仍有侵染力。通过PEG沉淀、差速离心、琼脂糖柱层析及蔗糖梯度离心,可得到较高浓度的纯化病毒,病毒的紫外吸收最低值在245nm,最高值在260nm。经SDS-PAGE测定,病毒外壳蛋白的分子量为2.7×10 ̄4道尔顿,病毒基因组核酸为三个组份,分子量分别为3.08kb,1.28kb和0.85kb。在琼脂双扩散实验中,能与番茄黑环病毒(TBRV)抗血清产生较弱的沉淀线,与黄瓜花叶病毒(CWV)、烟草环斑病毒(TRSV)、烟草坏死病毒(TNV)、香石竹环斑病毒(CaRSV)的抗血清不发生反应。 相似文献
106.
Summary The last decade has witnessed successful applications of plant tissue culture techniques in several crops. During that same
period, studies in plant molecular genetics have also grown exponentially. Molecular markers (isozymes, RFLPs, and PCR-based
markers such as RAPDs) are now used to study many of the current limitations of tissue culture. They have been used to investigate
mechanisms that underlie somaclonal variation in the nuclear, mitochondrial, and chloroplast genomes. One recurrent problem
with several tissue culture systems has been the difficulty of determining the origin of regenerants. Molecular markers represent
powerful tools to determine precisely the origin of plants derived from microspore or anther culture, protoplast fusion, and
other tissue culture studies where this information is important. With improvements in tissue culture techniques, populations
of doubled haploid lines have been produced in several major crop species. Doubled haploid populations have proven useful
in the production of molecular maps and in tagging important agronomic traits. This review describes the use of molecular
markers to address fundamental and practical questions of plant tissue culture, and discusses the potential of improvements
in molecular techniques and new molecular markers such as SCAR and STS along with high-resolution mapping strategies. 相似文献
107.
ABSTRACT. A microsporidian parasite, Nosema muscidifuracis n. sp., has been found in Muscidifurax raptor , a parasitoid of muscoid flies. Stages of the parasite developed in direct contact with the host cell cytoplasm and were detected in midgut epithelium, Malpighian tubules, ovaries (including oocytes) and fat body of larvae and adults. Spores were also detected within eggs deposited on the host. Light and electron microscopy revealed a developmental cycle with diplokaryotic stages dividing by binary fission and disporous sporulation sequences producing diplokaryotic spores of three morphological classes, differing significantly only in length of the polar filament. Two of the classes were found in larvae, pupae and adults. One of these, with about five turns in the coiled polar filament, is presumed to be responsible for transmission from cell to cell within the host (autoinfection) and the other, with about 10 turns, responsible for transmission from host to host. A third class, with about 15 turns in the polar filament, was found in eggs of M. raptor . It is, presumably, either involved in initiation and spread of the infection at eclosion or is responsible for horizontal transmission to a new host individual when eggs are cannibalized. 相似文献
108.
Jinzhao Hou Fen Wang Wallace L. McKeehan 《In vitro cellular & developmental biology. Animal》1994,30(2):111-114
Summary The human hepatoblastoma cell line, HepG2, exhibits an array of stable properties in culture that have made it a popular cell
culture model for studies on regulation of liver-specific gene expression and properties of hepatoma cells. In contrast to
other hepatoma cell lines, HepG2 cells overexpress a characteristic detergent-extractable, wheat germ lectin-binding protein
with apparent molecular mass of 130 kDa. Using an antibody to screen a phage expression library of HepG2 complementary DNA
(cDNA), we identified and cloned a 4734 base pair cDNA which codes for a 130-kDa leucine-rich protein (lrp130) when expressed
in transfected cells. The deduced sequence of lrp130 exhibits sequences weakly homologous to the consensus sequence for the
ATP binding site in ATP-dependent kinases and the protein kinase C phosphorylation site of the epidermal growth factor receptor.
Consistent with the higher levels of expression of lrp130 antigen, Northern hybridization analysis indicated that HepG2 cells
express high levels of the major 4.8 kilobase lrp130 mRNA relative to other hepatoma cells. Although currently of unknown
function, lrp130 may be of utility as a marker for liver cell lineages represented by the HepG2 cell line. 相似文献
109.
S. G. Tan J. S. F. Barker O. S. Selvaraj T. K. Mukherjee Y. F. Wong 《Biochemical genetics》1993,31(5-6):223-230
We have developed the methodologies for typing and family studies to establish the modes of inheritance of water buffalo red cell acid phosphatase (Acp), protease inhibitor (Pi), and group-specific component (Gc) on isoelectric focusing and albumin (Alb), red cell -esterase-3 (Est-3), and catalase (Cat) on polyacrylamide gel electrophoresis. Family studies showed that Pi, Gc, Alb, and Cat are coded by autosomal genes with two codominant alleles, while Est-3 is autosomal with two codominant alleles and a recessive null allele and Acp exhibits three codominant alleles.This project was funded by the Australian Centre for International Agricultural Research through Grant PN 8364 and the Malaysian programme for Intensification of Research in Priority Areas through Grant IRPA 1-07-05-057. 相似文献
110.
Jefferey Dole Kermit Ritland 《Evolution; international journal of organic evolution》1993,47(2):361-373
In mixed-mating plant populations, one can estimate the relative fitness of selfed progeny w by measuring the inbreeding coefficient F and selfing rate s of adults of one generation, together with F of adults in the following generation (after selection). In the first application of this multigenerational method, we estimated F and s for adults over three consecutive generations in adjacent populations of two annual Mimulus taxa: the outbreeding M. guttatus and the inbreeding M. platycalyx. This gave estimates of w for the last two generations. Although average multilocus selfing rates were high in both taxa (0.63 in M. guttatus; 0.84 in M. platycalyx), the relative fitness of selfed progeny averaged only 0.19 in M. guttatus and 0.32 in M. platycalyx. An alternative estimator for w that incorporates biparental inbreeding gave even lower estimates of w. These values are significantly below the 0.5 threshold thought to favor selfing, and show that partially selfing populations can harbor substantial genetic load. In accordance with the purging hypothesis, the more highly selfing M. platycalyx showed marginally lower inbreeding depression than M. guttatus in both years (P = 0.08). Inbreeding depression and selfing rates also varied among years in concert among taxa. Several sources of bias are discussed, but computer simulations indicate it is unlikely that w is biased downwards by linkage of marker loci to load loci. 相似文献